With the rapid development of digital image technology, traditional monochromatic electrophotographic printing is gradually being replaced by full color, high image quality electrophotographic printing. Electrophotographic printing technology enables the making of good quality in-house prints on-demand without requiring professional skills such as those skills used to perform conventional offset printing (lithographic printing) in a printing house.
The print quality of full color electrophotographic printing operations has traditionally been limited by characteristics of the print media, which is typically uncoated paper. To enhance the image quality of color electrophotographic printing, a coated print media such as coated paper designed for electrophotographic printing can be used. These coated print media are typically coated with inorganic pigment compositions and other functional materials configured to promote toner transfer and overall image quality. Additionally, these and other traditional print media coatings as well as traditional coatings processes are used to enhance the gloss and surface smoothness of the uncoated print media. For the coated print media, a calendaring procedure is often used to apply pressure and heat to the media to achieve high gloss and surface smoothness. However these types of coated media have a sheet gloss that is lower than what is necessary for photographic printing applications and often show a reduction in sheet gloss when the toner is fixed by a fuser in an electrophotographic printer.
Often, in order to achieve the desired high gloss and surface smoothness, printing media can be coated with functional materials on the image receiving side such as polyacrylic and polyester polymers. Such materials may, in some instances, be undesirable for some high end electrophotographic printers which employ high temperature and pressure fusing. With high fusing temperatures, the thermoplastic coating on the outermost layer of the media can be altered and gloss is subsequently reduced. Further, these materials may have a lower hardness, which frequently causes surface scratch problem during the printing process and post-usage. Moreover, many of the traditional film-forming coatings are solvent based, which is not environmental friendly in manufacture.